Roth Conversion plus Backdoor Roth

My Form 5498 shows a total of $46,000 as "Roth IRA conversion amount", which is the sum of a Roth Conversion plus my 'backdoor' Roth. 

($40K from an old 401K rolled to an IRA then immediately converted to Roth) + ( backdoor Roth of $6K which came from bank account and was contributed to IRA then immediately moved to Roth, both in 2021) 

 

Right now my 1040 line 4b shows $46,000 of additional taxable income. 

 

Since I already paid the tax on the $6k used for the backdoor Roth, and I did NOT take a deduction, it seems I am paying tax twice on the $6,000 backdoor Roth.

 

Where do I indicate the $6,000 I contributed to the IRA, for the backdoor Roth, was non-deductible so I am not double taxed?

 

What am I missing? 🙂